1. Field of the Invention
This invention relates to a method for manufacturing a semiconductor device.
2. Background Art
An IGBT (insulated gate bipolar transistor), which can achieve lower ON resistance than a vertical MOSFET (metal-oxide-semiconductor field effect transistor), is particularly suitable for use in high-current applications.
An IGBT with an anode short structure on the rear electrode side is also proposed (see, e.g., JP-A 2006-059876 (Kokai)). Formation of an anode short structure requires the step of selectively implanting dopant ions into the anode layer (collector layer). However, when the semiconductor wafer used has a structure where one of its surfaces is significantly recessed except its periphery, it is difficult to uniformly spin-coat the bottom of the recessed portion with a resist, which results in difficulty in forming a resist mask for selectively implanting dopant ions.